Phase shifters with switched transmission line loads

ABSTRACT

Apparatus and methods for phase shifters with switched transmission line loads are provided herein. In certain embodiments, a phase shifter includes a first port, a first controllable reflective load, a second port, a second controllable reflective load, and a pair of coupled lines that are electromagnetically coupled to one another. The pair of coupled lines includes a first conductive line between the first port and the first controllable reflective load and a second conductive line between the second controllable reflective load and the second port. At least one of the first controllable reflective load or the second controllable reflective load includes a switched transmission line load.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119 ofU.S. Provisional Patent Application No. 61/199,397, filed Dec. 23, 2020,and titled “PHASE SHIFTERS WITH SWITCHED TRANSMISSION LINE LOADS,” whichis herein incorporated by reference in its entirety.

BACKGROUND Technical Field

Embodiments of the invention relate to electronic systems, and inparticular, to radio frequency (RF) electronics.

Description of the Related Technology

Phase shifters are used in RF communication systems to control the phaseof RF signals transmitted or received wirelessly via antennas.

Examples of RF communication systems with one or more phase shiftersinclude, but are not limited to, mobile phones, tablets, base stations,network access points, customer-premises equipment (CPE), laptops, andwearable electronics. For example, in wireless devices that communicateusing a cellular standard, a wireless local area network (WLAN)standard, and/or any other suitable communication standard, a poweramplifier can be used for RF signal amplification. An RF signal can havea frequency in the range of about 30 kHz to 300 GHz, such as in therange of about 410 MHz to about 7.125 GHz for fifth generation (5G)communications using Frequency Range 1 (FR1) or in the range of about24.25 GHz to 52.6 GHz for 5G communications using Frequency Range 2(FR2).

SUMMARY

In certain embodiments, the present disclosure relates to a phaseshifter. The phase shifter includes a first port, a second port, a firstcontrollable reflective load including a first transmission line and afirst plurality of shunt switches connected along the first transmissionline, a second controllable reflective load, and a pair of coupled linesthat are electromagnetically coupled to one another. The pair of coupledlines including a first conductive line connected between the first portand the first controllable reflective load and a second conductive lineconnected between the second controllable reflective load and the secondport.

In some embodiments, the first controllable reflective load furtherincludes a first ground conductor on a first side of the firsttransmission line and a second ground conductor on a second side of thefirst transmission line. According to a number of embodiments, each ofthe first plurality of shunt switches is implemented as a pair offield-effect transistors including a first field-effect transistorconnected between the first transmission line and the first groundconductor and a second field-effect transistor connected between thefirst transmission line and the second ground conductor.

In several embodiments, one or more of the first plurality of shuntswitches are closed based on a phase shifting setting of the phaseshifter.

In various embodiments, the first port receives a radio frequency inputsignal and the second port provides a phase-shifted radio frequencyoutput signal.

In some embodiments, the second port receives a radio frequency inputsignal and the first port provides a phase-shifted radio frequencyoutput signal.

In several embodiments, the first plurality of shunt switches areconnected to the first transmission line at a plurality of points havinguninform distance from one another.

In various embodiments, the first plurality of shunt switches areconnected to the first transmission line at a plurality of points havingnon-uniform distance from one another. According to a number ofembodiments, the distance between adjacent pairs of the plurality ofpoints gradually decreases along a length of the first transmissionline.

In some embodiments, the first plurality of shunt switches each have acommon size.

In several embodiments, the first plurality of shunt switches each havea different size. According to a number of embodiments, the size of thefirst plurality of shunt transistors gradually increases along a lengthof the first transmission line.

In various embodiments, the first transmission line includes a pluralityof meandering sections. In accordance with some embodiments, at leastone of the plurality of meandering sections includes a loop.

In several embodiments, the second controllable reflective load includesa second transmission line and a second plurality of shunt switchesconnected along the second transmission line.

In some embodiments, the phase shifter further includes a hybrid couplerincluding the pair of coupled lines.

In certain embodiments, the present disclosure relates to a wirelessdevice. The wireless device includes a transceiver, and a front-endsystem coupled to the transceiver. The front-end system includes a phaseshifter including a first port, a second port, a first controllablereflective load including a first transmission line and a firstplurality of shunt switches connected along the first transmission line,a second controllable reflective load, and a pair of coupled lines thatare electromagnetically coupled to one another. The pair of coupledlines includes a first conductive line connected between the first portand the first controllable reflective load and a second conductive lineconnected between the second controllable reflective load and the secondport.

In various embodiments, the first controllable reflective load furtherincludes a first ground conductor on a first side of the firsttransmission line and a second ground conductor on a second side of thefirst transmission line. According to a number of embodiments, each ofthe first plurality of shunt switches is implemented as a pair offield-effect transistors including a first field-effect transistorconnected between the first transmission line and the first groundconductor and a second field-effect transistor connected between thefirst transmission line and the second ground conductor.

In several embodiments, one or more of the first plurality of shuntswitches are closed based on a phase shifting setting of the phaseshifter.

In some embodiments, the first port receives a radio frequency inputsignal and the second port provides a phase-shifted radio frequencyoutput signal.

In various embodiments, the second port receives a radio frequency inputsignal and the first port provides a phase-shifted radio frequencyoutput signal.

In several embodiments, the first plurality of shunt switches areconnected to the first transmission line at a plurality of points havinguninform distance from one another.

In some embodiments, the first plurality of shunt switches are connectedto the first transmission line at a plurality of points havingnon-uniform distance from one another. According to a number ofembodiments, the distance between adjacent pairs of the plurality ofpoints gradually decreases along a length of the first transmissionline.

In various embodiments, the first plurality of shunt switches each havea common size.

In several embodiments, the first plurality of shunt switches each havea different size. According to a number of embodiments, the size of thefirst plurality of shunt transistors gradually increases along a lengthof the first transmission line.

In some embodiments, the first transmission line includes a plurality ofmeandering sections. According to various embodiments, at least one ofthe plurality of meandering sections includes a loop.

In several embodiments, the second controllable reflective load includesa second transmission line and a second plurality of shunt switchesconnected along the second transmission line.

In various embodiments, the phase shifter further includes a hybridcoupler including the pair of coupled lines.

In certain embodiments, the present disclosure relates to a method ofphase shifting. The method includes receiving a radio frequency inputsignal at a first port. The method further includes controlling a firstcontrollable reflective load and a second controllable reflective loadto control a phase shift of a radio frequency output signal at a secondport, the first controllable reflective load including a firsttransmission line and a first plurality of shunt switches connectedalong the first transmission line. The method further includes providingcoupling between a first conductive line and a second conductive line ofa pair of coupled lines, the first conductive line connected between thefirst port and the first controllable reflective load, and the secondconductive line connected between the second controllable reflectiveload and the second port.

In various embodiments, the first controllable reflective load furtherincludes a first ground conductor on a first side of the firsttransmission line and a second ground conductor on a second side of thefirst transmission line. According to several embodiments, each of thefirst plurality of shunt switches is implemented as a pair offield-effect transistors including a first field-effect transistorconnected between the first transmission line and the first groundconductor and a second field-effect transistor connected between thefirst transmission line and the second ground conductor.

In a number of embodiments, the method further includes closing one ormore of the first plurality of shunt switches based on a phase shiftingsetting of the phase shifter.

In several embodiments, the first plurality of shunt switches areconnected to the first transmission line at a plurality of points havinguninform distance from one another.

In various embodiments, the first plurality of shunt switches areconnected to the first transmission line at a plurality of points havingnon-uniform distance from one another. According to a number ofembodiments, the distance between adjacent pairs of the plurality ofpoints gradually decreases along a length of the first transmissionline.

In several embodiments, the first plurality of shunt switches each havea common size.

In some embodiments, the first plurality of shunt switches each have adifferent size. In accordance with various embodiments, the size of thefirst plurality of shunt transistors gradually increases along a lengthof the first transmission line.

In a number of embodiments, the first transmission line includes aplurality of meandering sections. According to several embodiments, atleast one of the plurality of meandering sections includes a loop.

In various embodiments, the second controllable reflective load includesa second transmission line and a second plurality of shunt switchesconnected along the second transmission line.

In some embodiments, the phase shifter further includes a hybrid couplerincluding the pair of coupled lines.

In certain embodiments, the present disclosure relates to a phaseshifter. The phase shifter includes a coupler including an inputterminal, a thru terminal, a first coupled line connected between theinput terminal and the thru terminal, an isolation terminal, a couplingterminal, and a second coupled line connected between the isolationterminal and the coupling terminal. The phase shifter further includesan input port connected to the input terminal of the coupler andconfigured to receive a radio frequency input signal, an output portconnected to the coupling terminal of the coupler and configured tooutput a radio frequency output signal having a phase shift with respectto the radio frequency input signal, and a first controllable reflectiveload connected to the thru terminal of the coupler. The firstcontrollable reflective load includes a transmission line and aplurality of shunt switches each connected between a ground voltage anda different point along the transmission line, the plurality of shuntswitches selectable to control the phase shift.

In various embodiments, the first controllable reflective load furtherincludes a first ground conductor on a first side of the transmissionline and a second ground conductor on a second side of the transmissionline. According to a number of embodiments, each of the plurality ofshunt switches is implemented as a pair of field-effect transistorsincluding a first field-effect transistor connected between thetransmission line and the first ground conductor and a secondfield-effect transistor connected between the transmission line and thesecond ground conductor.

In several embodiments, the plurality of shunt switches are connected tothe transmission line at a plurality of points that are non-uniformlyspaced. According to a number of embodiments, a distance betweenadjacent pairs of the plurality of points gradually decreases along alength of the transmission line.

In various embodiments, the plurality of shunt switches each have adifferent size. According to a number of embodiments, the size of theplurality of shunt transistors gradually increases along a length of thefirst transmission line.

In several embodiments, the transmission line includes a plurality ofmeandering sections. According to some embodiments, at least one of theplurality of meandering sections includes a loop.

In a number of embodiments, the phase shifter further includes a secondcontrollable reflective load connected to the isolation terminal of thecoupler.

In certain embodiments, the present disclosure relates to a wirelessdevice. The wireless device includes a transceiver, and a front-endsystem coupled to the transceiver. The front-end system includes a phaseshifter including a coupler having an input terminal configured toreceive a radio frequency input signal, a thru terminal, a first coupledline connected between the input terminal and the thru terminal, anisolation terminal, a coupling terminal configured to output a radiofrequency output signal having a phase shift with respect to the radiofrequency input signal, and a second coupled line connected between theisolation terminal and the coupling terminal. The phase shifter furtherincludes a first controllable reflective load connected to the thruterminal of the coupler and including a transmission line and aplurality of shunt switches each connected between a ground voltage anda different point along the transmission line, the plurality of shuntswitches selectable to control the phase shift.

In some embodiments, the first controllable reflective load furtherincludes a first ground conductor on a first side of the transmissionline and a second ground conductor on a second side of the transmissionline. According to a number of embodiments, each of the plurality ofshunt switches is implemented as a pair of field-effect transistorsincluding a first field-effect transistor connected between thetransmission line and the first ground conductor and a secondfield-effect transistor connected between the transmission line and thesecond ground conductor.

In various embodiments, the plurality of shunt switches are connected tothe transmission line at a plurality of points that are non-uniformlyspaced. According to some embodiments, a distance between adjacent pairsof the plurality of points gradually decreases along a length of thetransmission line.

In several embodiments, the plurality of shunt switches each have adifferent size. According to a number of embodiments, the size of theplurality of shunt transistors gradually increases along a length of thefirst transmission line.

In some embodiments, the mobile device further includes a secondcontrollable reflective load connected to the isolation terminal of thecoupler.

In certain embodiments, the present disclosure relates to a method ofphase shifting. The method includes receiving a radio frequency inputsignal at an input terminal of a coupler. The method further includesproviding coupling from a first coupled line of the coupler to a secondcoupled line of the coupler, the first coupled line connected betweenthe input terminal of the coupler and a thru terminal of the coupler,and the second coupled line connected between an isolation terminal ofthe coupler and a coupling terminal of the coupler. The method furtherincludes providing a radio frequency output signal from the couplingterminal of the coupler, the radio frequency output signal having aphase shift with respect to the radio frequency input signal. The methodfurther includes controlling the phase shift using a first controllablereflective load connected to the thru terminal of the coupler, includingselecting one or more of a plurality of shunt switches of the firstcontrollable reflective load, each of the plurality of shunt switchesconnected between a ground voltage and a different point along atransmission line of the first controllable reflective load.

In some embodiments, the method further includes controlling a secondcontrollable reflective load connected to the isolation terminal of thecoupler.

In certain embodiments, the present disclosure relates to a phaseshifter. The phase shifter includes a first port, a second port, a firstcontrollable reflective load, and a second controllable reflective loadincluding a first transmission line and a first plurality of shuntswitches connected along the first transmission line. The phase shifterfurther includes a pair of coupled lines that are electromagneticallycoupled to one another. The pair of coupled lines includes a firstconductive line connected between the first port and the firstcontrollable reflective load and a second conductive line connectedbetween the second controllable reflective load and the second port.

In various embodiments, the second controllable reflective load furtherincludes a first ground conductor on a first side of the firsttransmission line and a second ground conductor on a second side of thefirst transmission line. According to several embodiments, each of thefirst plurality of shunt switches is implemented as a pair offield-effect transistors including a first field-effect transistorconnected between the first transmission line and the first groundconductor and a second field-effect transistor connected between thefirst transmission line and the second ground conductor.

In a number of embodiments, one or more of the first plurality of shuntswitches are closed based on a phase shifting setting of the phaseshifter.

In some embodiments, the first port receives a radio frequency inputsignal and the second port provides a phase-shifted radio frequencyoutput signal.

In several embodiments, the second port receives a radio frequency inputsignal and the first port provides a phase-shifted radio frequencyoutput signal.

In various embodiments, the first plurality of shunt switches areconnected to the first transmission line at a plurality of points havinguninform distance from one another.

In some embodiments, the first plurality of shunt switches are connectedto the first transmission line at a plurality of points havingnon-uniform distance from one another. According to a number ofembodiments, the distance between adjacent pairs of the plurality ofpoints gradually decreases along a length of the first transmissionline.

In several embodiments, the first plurality of shunt switches each havea common size.

In a number of embodiments, the first plurality of shunt switches eachhave a different size. According to some embodiments, the size of thefirst plurality of shunt transistors gradually increases along a lengthof the first transmission line.

In various embodiments, the first transmission line includes a pluralityof meandering sections. According to a number of embodiments, at leastone of the plurality of meandering sections includes a loop.

In several embodiments, the first controllable reflective load includesa second transmission line and a second plurality of shunt switchesconnected along the second transmission line.

In some embodiments, the phase shifter further includes a hybrid couplerincluding the pair of coupled lines.

In certain embodiments, the present disclosure relates to a wirelessdevice. The wireless device includes a transceiver and a front-endsystem coupled to the transceiver. The front-end system includes a phaseshifter including a first port, a second port, a first controllablereflective load, a second controllable reflective load including a firsttransmission line and a first plurality of shunt switches connectedalong the first transmission line. The phase shifter further includes apair of coupled lines that are electromagnetically coupled to oneanother. The pair of coupled lines includes a first conductive lineconnected between the first port and the first controllable reflectiveload and a second conductive line connected between the secondcontrollable reflective load and the second port.

In various embodiments, the second controllable reflective load furtherincludes a first ground conductor on a first side of the firsttransmission line and a second ground conductor on a second side of thefirst transmission line. According to a number of embodiments, each ofthe first plurality of shunt switches is implemented as a pair offield-effect transistors including a first field-effect transistorconnected between the first transmission line and the first groundconductor and a second field-effect transistor connected between thefirst transmission line and the second ground conductor.

In several embodiments, one or more of the first plurality of shuntswitches are closed based on a phase shifting setting of the phaseshifter.

In various embodiments, the first port receives a radio frequency inputsignal and the second port provides a phase-shifted radio frequencyoutput signal.

In some embodiments, the second port receives a radio frequency inputsignal and the first port provides a phase-shifted radio frequencyoutput signal.

In a number of embodiments, the first plurality of shunt switches areconnected to the first transmission line at a plurality of points havinguninform distance from one another.

In several embodiments, the first plurality of shunt switches areconnected to the first transmission line at a plurality of points havingnon-uniform distance from one another. According to a number ofembodiments, the distance between adjacent pairs of the plurality ofpoints gradually decreases along a length of the first transmissionline.

In various embodiments, the first plurality of shunt switches each havea common size.

In several embodiments, the first plurality of shunt switches each havea different size. According to some embodiments, the size of the firstplurality of shunt transistors gradually increases along a length of thefirst transmission line.

In a number of embodiments, the first transmission line includes aplurality of meandering sections. According to various embodiments, atleast one of the plurality of meandering sections includes a loop.

In some embodiments, the first controllable reflective load includes asecond transmission line and a second plurality of shunt switchesconnected along the second transmission line.

In several embodiments, the phase shifter further includes a hybridcoupler including the pair of coupled lines.

In certain embodiments, a method of phase shifting is provided. Themethod includes receiving a radio frequency input signal at a firstport. The method further includes controlling a first controllablereflective load and a second controllable reflective load to control aphase shift of a radio frequency output signal at a second port, thefirst controllable reflective load including a first transmission lineand a first plurality of shunt switches connected along the firsttransmission line. The method further includes providing couplingbetween a first conductive line and a second conductive line of a pairof coupled lines, the first conductive line connected between the firstport and the first controllable reflective load, and the secondconductive line connected between the second controllable reflectiveload and the second port.

In several embodiments, the second controllable reflective load furtherincludes a first ground conductor on a first side of the firsttransmission line and a second ground conductor on a second side of thefirst transmission line. According to some embodiments, each of thefirst plurality of shunt switches is implemented as a pair offield-effect transistors including a first field-effect transistorconnected between the first transmission line and the first groundconductor and a second field-effect transistor connected between thefirst transmission line and the second ground conductor.

In a number of embodiments, the method further includes closing one ormore of the first plurality of shunt switches based on a phase shiftingsetting of the phase shifter.

In various embodiments, the first plurality of shunt switches areconnected to the first transmission line at a plurality of points havinguninform distance from one another.

In several embodiments, the first plurality of shunt switches areconnected to the first transmission line at a plurality of points havingnon-uniform distance from one another. According to a number ofembodiments, the distance between adjacent pairs of the plurality ofpoints gradually decreases along a length of the first transmissionline.

In various embodiments, the first plurality of shunt switches each havea common size.

In some embodiments, the first plurality of shunt switches each have adifferent size. According to a number of embodiments, the size of thefirst plurality of shunt transistors gradually increases along a lengthof the first transmission line.

In several embodiments, the first transmission line includes a pluralityof meandering sections. According to a number of embodiments, at leastone of the plurality of meandering sections includes a loop.

In various embodiments, the first controllable reflective load includesa second transmission line and a second plurality of shunt switchesconnected along the second transmission line.

In some embodiments, the phase shifter further includes a hybrid couplerincluding the pair of coupled lines.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of this disclosure will now be described, by way ofnon-limiting example, with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of one example of a communication network.

FIG. 2A is a schematic diagram of one embodiment of a communicationsystem that operates with beamforming.

FIG. 2B is a schematic diagram of one embodiment of beamforming toprovide a transmit beam.

FIG. 2C is a schematic diagram of one embodiment of beamforming toprovide a receive beam.

FIG. 3 is a schematic diagram of a phase shifter according to oneembodiment.

FIG. 4A is a schematic diagram of a switched transmission line accordingto one embodiment.

FIG. 4B is a schematic diagram of a switched transmission line accordingto another embodiment.

FIG. 5A is a schematic diagram of a switched transmission line accordingto another embodiment.

FIG. 5B is a schematic diagram of a switched transmission line accordingto another embodiment.

FIG. 6 is a schematic diagram of a switched transmission line accordingto another embodiment.

FIG. 7 is a schematic diagram of a switched transmission line accordingto another embodiment.

FIG. 8 is a schematic diagram of one embodiment of a mobile device.

FIG. 9A is a schematic diagram of an RF channel according to oneembodiment.

FIG. 9B is a schematic diagram of an RF channel according to anotherembodiment.

FIG. 10A is a perspective view of one embodiment of a module thatoperates with beamforming.

FIG. 10B is a cross-section of the module of FIG. 10A taken along thelines 10B-10B.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The following detailed description of certain embodiments presentsvarious descriptions of specific embodiments. However, the innovationsdescribed herein can be embodied in a multitude of different ways, forexample, as defined and covered by the claims. In this description,reference is made to the drawings where like reference numerals canindicate identical or functionally similar elements. It will beunderstood that elements illustrated in the figures are not necessarilydrawn to scale. Moreover, it will be understood that certain embodimentscan include more elements than illustrated in a drawing and/or a subsetof the elements illustrated in a drawing. Further, some embodiments canincorporate any suitable combination of features from two or moredrawings.

The International Telecommunication Union (ITU) is a specialized agencyof the United Nations (UN) responsible for global issues concerninginformation and communication technologies, including the shared globaluse of radio spectrum.

The 3rd Generation Partnership Project (3GPP) is a collaboration betweengroups of telecommunications standard bodies across the world, such asthe Association of Radio Industries and Businesses (ARIB), theTelecommunications Technology Committee (TTC), the China CommunicationsStandards Association (CCSA), the Alliance for TelecommunicationsIndustry Solutions (ATIS), the Telecommunications Technology Association(TTA), the European Telecommunications Standards Institute (ETSI), andthe Telecommunications Standards Development Society, India (TSDSI).

Working within the scope of the ITU, 3GPP develops and maintainstechnical specifications for a variety of mobile communicationtechnologies, including, for example, second generation (2G) technology(for instance, Global System for Mobile Communications (GSM) andEnhanced Data Rates for GSM Evolution (EDGE)), third generation (3G)technology (for instance, Universal Mobile Telecommunications System(UMTS) and High Speed Packet Access (HSPA)), and fourth generation (4G)technology (for instance, Long Term Evolution (LTE) and LTE-Advanced).

The technical specifications controlled by 3GPP can be expanded andrevised by specification releases, which can span multiple years andspecify a breadth of new features and evolutions.

In one example, 3GPP introduced carrier aggregation (CA) for LTE inRelease 10. Although initially introduced with two downlink carriers,3GPP expanded carrier aggregation in Release 14 to include up to fivedownlink carriers and up to three uplink carriers. Other examples of newfeatures and evolutions provided by 3GPP releases include, but are notlimited to, License Assisted Access (LAA), enhanced LAA (eLAA),Narrowband Internet of things (NB-IOT), Vehicle-to-Everything (V2X), andHigh Power User Equipment (HPUE).

3GPP introduced Phase 1 of fifth generation (5G) technology in Release15, and introduced Phase 2 of 5G technology in Release 16. Subsequent3GPP releases will further evolve and expand 5G technology. 5Gtechnology is also referred to herein as 5G New Radio (NR).

5G NR supports or plans to support a variety of features, such ascommunications over millimeter wave spectrum, beamforming capability,high spectral efficiency waveforms, low latency communications, multipleradio numerology, and/or non-orthogonal multiple access (NOMA). Althoughsuch RF functionalities offer flexibility to networks and enhance userdata rates, supporting such features can pose a number of technicalchallenges.

The teachings herein are applicable to a wide variety of communicationsystems, including, but not limited to, communication systems usingadvanced cellular technologies, such as LTE-Advanced, LTE-Advanced Pro,and/or 5G NR.

FIG. 1 is a schematic diagram of one example of a communication network10. The communication network 10 includes a macro cell base station 1, asmall cell base station 3, and various examples of user equipment (UE),including a first mobile device 2 a, a wireless-connected car 2 b, alaptop 2 c, a stationary wireless device 2 d, a wireless-connected train2 e, a second mobile device 2 f, and a third mobile device 2 g.

Although specific examples of base stations and user equipment areillustrated in FIG. 1, a communication network can include base stationsand user equipment of a wide variety of types and/or numbers.

For instance, in the example shown, the communication network 10includes the macro cell base station 1 and the small cell base station3. The small cell base station 3 can operate with relatively lowerpower, shorter range, and/or with fewer concurrent users relative to themacro cell base station 1. The small cell base station 3 can also bereferred to as a femtocell, a picocell, or a microcell. Although thecommunication network 10 is illustrated as including two base stations,the communication network 10 can be implemented to include more or fewerbase stations and/or base stations of other types.

Although various examples of user equipment are shown, the teachingsherein are applicable to a wide variety of user equipment, including,but not limited to, mobile phones, tablets, laptops, IoT devices,wearable electronics, customer premises equipment (CPE),wireless-connected vehicles, wireless relays, and/or a wide variety ofother communication devices. Furthermore, user equipment includes notonly currently available communication devices that operate in acellular network, but also subsequently developed communication devicesthat will be readily implementable with the inventive systems,processes, methods, and devices as described and claimed herein.

The illustrated communication network 10 of FIG. 1 supportscommunications using a variety of cellular technologies, including, forexample, 4G LTE and 5G NR. In certain implementations, the communicationnetwork 10 is further adapted to provide a wireless local area network(WLAN), such as WiFi. Although various examples of communicationtechnologies have been provided, the communication network 10 can beadapted to support a wide variety of communication technologies.

Various communication links of the communication network 10 have beendepicted in FIG. 1. The communication links can be duplexed in a widevariety of ways, including, for example, using frequency-divisionduplexing (FDD) and/or time-division duplexing (TDD). FDD is a type ofradio frequency communications that uses different frequencies fortransmitting and receiving signals. FDD can provide a number ofadvantages, such as high data rates and low latency. In contrast, TDD isa type of radio frequency communications that uses about the samefrequency for transmitting and receiving signals, and in which transmitand receive communications are switched in time. TDD can provide anumber of advantages, such as efficient use of spectrum and variableallocation of throughput between transmit and receive directions.

In certain implementations, user equipment can communicate with a basestation using one or more of 4G LTE, 5G NR, and WiFi technologies. Incertain implementations, enhanced license assisted access (eLAA) is usedto aggregate one or more licensed frequency carriers (for instance,licensed 4G LTE and/or 5G NR frequencies), with one or more unlicensedcarriers (for instance, unlicensed WiFi frequencies).

As shown in FIG. 1, the communication links include not onlycommunication links between UE and base stations, but also UE to UEcommunications and base station to base station communications. Forexample, the communication network 10 can be implemented to supportself-fronthaul and/or self-backhaul (for instance, as between mobiledevice 2 g and mobile device 2 f).

The communication links can operate over a wide variety of frequencies.In certain implementations, communications are supported using 5G NRtechnology over one or more frequency bands that are less than 6Gigahertz (GHz) and/or over one or more frequency bands that are greaterthan 6 GHz. For example, the communication links can serve FrequencyRange 1 (FR1), Frequency Range 2 (FR2), or a combination thereof. In oneembodiment, one or more of the mobile devices support a HPUE power classspecification.

In certain implementations, a base station and/or user equipmentcommunicates using beamforming. For example, beamforming can be used tofocus signal strength to overcome path losses, such as high lossassociated with communicating over high signal frequencies. In certainembodiments, user equipment, such as one or more mobile phones,communicate using beamforming on millimeter wave frequency bands in therange of 30 GHz to 300 GHz and/or upper centimeter wave frequencies inthe range of 6 GHz to 30 GHz, or more particularly, 24 GHz to 30 GHz.

Different users of the communication network 10 can share availablenetwork resources, such as available frequency spectrum, in a widevariety of ways.

In one example, frequency division multiple access (FDMA) is used todivide a frequency band into multiple frequency carriers. Additionally,one or more carriers are allocated to a particular user. Examples ofFDMA include, but are not limited to, single carrier FDMA (SC-FDMA) andorthogonal FDMA (OFDMA). OFDMA is a multicarrier technology thatsubdivides the available bandwidth into multiple mutually orthogonalnarrowband subcarriers, which can be separately assigned to differentusers.

Other examples of shared access include, but are not limited to, timedivision multiple access (TDMA) in which a user is allocated particulartime slots for using a frequency resource, code division multiple access(CDMA) in which a frequency resource is shared amongst different usersby assigning each user a unique code, space-divisional multiple access(SDMA) in which beamforming is used to provide shared access by spatialdivision, and non-orthogonal multiple access (NOMA) in which the powerdomain is used for multiple access. For example, NOMA can be used toserve multiple users at the same frequency, time, and/or code, but withdifferent power levels.

Enhanced mobile broadband (eMBB) refers to technology for growing systemcapacity of LTE networks. For example, eMBB can refer to communicationswith a peak data rate of at least 10 Gbps and a minimum of 100 Mbps foreach user. Ultra-reliable low latency communications (uRLLC) refers totechnology for communication with very low latency, for instance, lessthan 2 milliseconds. uRLLC can be used for mission-criticalcommunications such as for autonomous driving and/or remote surgeryapplications. Massive machine-type communications (mMTC) refers to lowcost and low data rate communications associated with wirelessconnections to everyday objects, such as those associated with Internetof Things (IoT) applications.

The communication network 10 of FIG. 1 can be used to support a widevariety of advanced communication features, including, but not limitedto, eMBB, uRLLC, and/or mMTC.

FIG. 2A is a schematic diagram of one embodiment of a communicationsystem 110 that operates with beamforming. The communication system 110includes a transceiver 105, signal conditioning circuits 104 a 1, 104 a2 . . . 104 an, 104 b 1, 104 b 2 . . . 104 bn, 104 m 1, 104 m 2 . . .104 mn, and an antenna array 102 that includes antenna elements 103 a 1,103 a 2 . . . 103 an, 103 b 1, 103 b 2 . . . 103 bn, 103 m 1, 103 m 2 .. . 103 mn.

Communications systems that communicate using millimeter wave carriers,centimeter wave carriers, and/or other frequency carriers can employ anantenna array such as the antenna array 102 to provide beam formationand directivity for transmission and/or reception of signals.

For example, in the illustrated embodiment, the communication system 110includes an array 102 of m×n antenna elements, each of which are coupledto a separate signal conditioning circuit, in this embodiment. Asindicated by the ellipses, the communication system 110 can beimplemented with any suitable number of antenna elements and signalconditioning circuits.

With respect to signal transmission, the signal conditioning circuits104 a 1, 104 a 2 . . . 104 an, 104 b 1, 104 b 2 . . . 104 bn, 104 m 1,104 m 2 . . . 104 mn can provide transmit signals to the antenna array102 such that signals radiated from the antenna elements combine usingconstructive and destructive interference to generate an aggregatetransmit signal exhibiting beam-like qualities with more signal strengthpropagating in a given direction away from the antenna array 102.

In the context of signal reception, the signal conditioning circuits 104a 1, 104 a 2 . . . 104 an, 104 b 1, 104 b 2 . . . 104 bn, 104 m 1, 104 m2 . . . 104 mn process the received signals (for instance, by separatelycontrolling received signal phases) such that more signal energy isreceived when the signal is arriving at the antenna array 102 from aparticular direction. Accordingly, the communication system 110 alsoprovides directivity for reception of signals.

The relative concentration of signal energy into a transmit beam or areceive beam can be enhanced by increasing the size of the array. Forexample, with more signal energy focused into a transmit beam, thesignal is able to propagate for a longer range while providingsufficient signal level for RF communications. For instance, a signalwith a large proportion of signal energy focused into the transmit beamcan exhibit high effective isotropic radiated power (EIRP).

In the illustrated embodiment, the transceiver 105 provides transmitsignals to the signal conditioning circuits 104 a 1, 104 a 2 . . . 104an, 104 b 1, 104 b 2 . . . 104 bn, 104 m 1, 104 m 2 . . . 104 mn andprocesses signals received from the signal conditioning circuits.

As shown in FIG. 2A, the transceiver 105 generates control signals forthe signal conditioning circuits 104 a 1, 104 a 2 . . . 104 an, 104 b 1,104 b 2 . . . 104 bn, 104 m 1, 104 m 2 . . . 104 mn. The control signalscan be used for a variety of functions, such as controlling the gain andphase of transmitted and/or received signals to control beamforming. Forexample, each of the signal conditioning circuits 104 a 1, 104 a 2 . . .104 an, 104 b 1, 104 b 2 . . . 104 bn, 104 m 1, 104 m 2 . . . 104 mn caninclude a phase shifter implemented in accordance with the teachingsherein.

FIG. 2B is a schematic diagram of one embodiment of beamforming toprovide a transmit beam. FIG. 2B illustrates a portion of acommunication system including a first signal conditioning circuit 114a, a second signal conditioning circuit 114 b, a first antenna element113 a, and a second antenna element 113 b.

Although illustrated as included two antenna elements and two signalconditioning circuits, a communication system can include additionalantenna elements and/or signal conditioning circuits. For example, FIG.2B illustrates one embodiment of a portion of the communication system110 of FIG. 2A.

The first signal conditioning circuit 114 a includes a first phaseshifter 130 a, a first power amplifier 131 a, a first low noiseamplifier (LNA) 132 a, and switches for controlling selection of thepower amplifier 131 a or LNA 132 a. Additionally, the second signalconditioning circuit 114 b includes a second phase shifter 130 b, asecond power amplifier 131 b, a second LNA 132 b, and switches forcontrolling selection of the power amplifier 131 b or LNA 132 b. Thefirst phase shifter 130 a and the second phase shifter 130 b can beimplemented in accordance with any of the embodiments herein.

Although one embodiment of signal conditioning circuits is shown, otherimplementations of signal conditioning circuits are possible. Forinstance, in one example, a signal conditioning circuit includes one ormore band filters, duplexers, diplexers, and/or other components.

In the illustrated embodiment, the first antenna element 113 a and thesecond antenna element 113 b are separated by a distance d.Additionally, FIG. 2B has been annotated with an angle θ, which in thisexample has a value of about 90° when the transmit beam direction issubstantially perpendicular to a plane of the antenna array and a valueof about 0° when the transmit beam direction is substantially parallelto the plane of the antenna array.

By controlling the relative phase of the transmit signals provided tothe antenna elements 113 a, 113 b, a desired transmit beam angle θ canbe achieved. For example, when the first phase shifter 130 a has areference value of 0°, the second phase shifter 130 b can be controlledto provide a phase shift of about −2πf(d/ν)cos θ radians, where f is thefundamental frequency of the transmit signal, d is the distance betweenthe antenna elements, ν is the velocity of the radiated wave, and π isthe mathematic constant pi.

In certain implementations, the distance d is implemented to be about½λ, where λ is the wavelength of the fundamental component of thetransmit signal. In such implementations, the second phase shifter 130 bcan be controlled to provide a phase shift of about −π cos θ radians toachieve a transmit beam angle θ.

Accordingly, the relative phase of the phase shifters 130 a, 130 b canbe controlled to provide transmit beamforming. In certainimplementations, a transceiver (for example, the transceiver 105 of FIG.2A) controls phase values of one or more phase shifters to controlbeamforming.

FIG. 2C is a schematic diagram of one embodiment of beamforming toprovide a receive beam. FIG. 2C is similar to FIG. 2B, except that FIG.2C illustrates beamforming in the context of a receive beam rather thana transmit beam.

As shown in FIG. 2C, a relative phase difference between the first phaseshifter 130 a and the second phase shifter 130 b can be selected toabout equal to −πf(d/ν)cos θ radians to achieve a desired receive beamangle θ. In implementations in which the distance d corresponds to about½λ, the phase difference can be selected to about equal to −π cos θradians to achieve a receive beam angle θ.

Although various equations for phase values to provide beamforming havebeen provided, other phase selection values are possible, such as phasevalues selected based on implementation of an antenna array,implementation of signal conditioning circuits, and/or a radioenvironment.

Phase Shifters with Switched Transmission Line Loads

Phase shifters are used in radio frequency (RF) systems to provide acontrollable phase adjustment to an RF signal.

Phase shifters with switched transmission line loads are providedherein. In certain embodiments, a phase shifter includes a first port, afirst controllable reflective load, a second port, a second controllablereflective load, and a pair of coupled lines that areelectromagnetically coupled to one another. The pair of coupled linesincludes a first conductive line between the first port and the firstcontrollable reflective load and a second conductive line between thesecond controllable reflective load and the second port. At least one ofthe first controllable reflective load or the second controllablereflective load includes a switched transmission line load.

By implementing the phase shifter in this manner, high frequencyperformance (for instance, operation in FR2 such as in the 24 GHz to 30GHz range) is enabled. Moreover, good return loss can be achieved and/orthe return loss can be relatively constant across the range of phasesettings of the phase shifter. Furthermore, the group delay of the phaseshifter has little to no variation with frequency, and thus does notdistort wideband signals.

The first controllable reflective load and the second controllablereflective load are controlled based on a chosen phase setting of thephase shifter. In certain implementations, each controllable reflectiveload is implemented using a switched transmission line load. Suchswitched transmission line loads can include a transmission line andshunt switches (for instance, field-effect transistors or FETs)connected between the transmission line and a reference voltage, such asground. By selecting the combination of switches that are turned on, aneffective electrical length of the transmission line can be controlled.As the effective electrical length changes, amount of phase shiftprovided by the phase shifter is also varied.

The even mode impedance, odd mode impedance, and length of the pair ofcoupled lines can be adjusted during design to achieve desiredperformance characteristics. In certain implementations, the pair ofcoupled lines is implemented as a coupler, such as a 3-dB ninety degree90° coupler (also referred to herein as a hybrid coupler). The hybridcoupler operates in combination with the controllable reflective loadsto achieve desired performance.

The phase shifters herein can be used in a wide variety of applications,including, but not limited to, providing phase shifting in RF signalconditional circuits for a beamforming application.

In certain implementations herein, a phase shifter is configured toprovide phase shifting to an RF signal in frequency range 2 (FR2) of 5G,for instance, 24.25 GHz to 52.6 GHz. However, the phase shifters hereincan handle other RF signal frequencies.

FIG. 3 is a schematic diagram of a phase shifter 210 according to oneembodiment. The phase shifter 210 includes a pair of coupled lines 200(corresponding to a hybrid coupler, in this embodiment), a firstcontrollable reflective load 201 (also referred to herein as a variablereflective load), a second controllable reflective load 202, an inputport IN, and an output port OUT. The coupled lines 200 includes a firstconductive line 203 and a second conductive line 204 that areelectromagnetically coupled to one another.

In the illustrated embodiment, a first end 207 a of the first conduciveline 203 is connected to the input port IN and a second end 207 b of thefirst conductive line 203 is connected to the first controllablereflective load 201. Additionally, a first end 208 a of the secondconductive line 204 is connected to the second controllable reflectiveload 202 and a second end 208 b of the second conducive line 204 isconnected to the output port OUT. The first end 207 a of the firstconductive line 203 and the first end 208 a of the second conductiveline 204 are on a first side of the coupled lines 200, while the secondend 207 b of the first conductive line 203 and the second end 208 b ofthe second conductive line 204 are on a second or opposite side of thecoupled lines 200.

The pair of coupled lines 200 is implemented as a hybrid coupler, inthis embodiment. Additionally, the first end 207 a corresponds to aninput terminal (IN) of the coupler, the second end 207 b corresponds toa thru terminal (0°) of the coupler, the first end 208 a corresponds toan isolation terminal (ISO) of the coupler, and the second end 208 bcorresponds to a coupling terminal (90°) of the coupler.

At least one of the first controllable reflective load 201 or the secondcontrollable reflective load 202 is implemented using a switchedtransmission line in accordance with the teachings herein.

By implementing the phase shifter 210 in this manner, high frequencyperformance, good return loss, and/or constant return loss across phasesettings can be achieved. Furthermore, the group delay of the phaseshifter 210 has little to no variation with frequency, and thus does notdistort wideband signals.

In certain implementations, the first controllable reflective load 201and the second controllable reflective load 202 are controlled based ona chosen phase setting of the phase shifter 210 to thereby change theelectrical length of the transmission lines of the reflective loads. Forexample, the first controllable reflective load 201 and the secondcontrollable reflective load 202 can each be implemented as a switchedtransmission line controlled by a common control signal.

The even mode impedance, odd mode impedance, and length of the coupledlines 200 can be adjusted during design to achieve desired performancecharacteristics. The coupled lines 200 operates in combination with thecontrollable reflective loads 201/202 to achieve desired performance.

FIG. 4A is a schematic diagram of a switched transmission line 230according to one embodiment. The switched transmission line 230 includesa transmission line 221, an RF input RF_(IN) to the transmission line221, shunt switches 222 a, 222 b, 222 c, . . . 222 n, and a controlcircuit 223. Thus, n shunt switches are included, where n is an integerof 2 or more, or more preferably, 4 or more.

The switched transmission line 230 of FIG. 4A illustrates one embodimentof a controllable reflective load implemented in accordance with theteachings herein.

In the illustrated embodiment, the control circuit 223 opens or closesthe shunt switches 222 a, 222 b, 222 c, . . . 222 n based on a selectedphase shifting setting φ. The shunt switches 222 a, 222 b, 222 c, . . .222 n are connected to different positions along the transmission line221. The shunt switches 222 a, 222 b, 222 c, . . . 222 n selectivelyconnect the transmission line 221 to ground.

By changing which of the shunt switches 222 a, 222 b, 222 c, . . . 222 nare turned on and which are turned off, the electrical length of thetransmission line 221 is changed. This in turn impacts the overall phaseshift of a reflective type phase shifter in which the switchedtransmission line 230 is incorporated.

In certain implementations, the control circuit 223 turns on allswitches (or at least the shunt switch 222 a closest to RF_(IN)) toprovide the shortest electrical length of the transmission line 221.When starting at a state with all shunt switches closed, progressivelylonger electrical lengths can be provided by sequentially opening(turning off) the shunt switches, beginning with the switch 222 aclosest to RF_(IN).

FIG. 4B is a schematic diagram of a switched transmission line 230′according to another embodiment.

The switched transmission line 230′ of FIG. 4B is similar to theswitched transmission line 230 of FIG. 4A, except that the switchedtransmission line 230′ of FIG. 4B includes a control circuit 223′including a thermometer decoder 224.

In certain embodiments herein, a switched transmission line includesshunt switches that are controlled using thermometer coding.

FIG. 5A is a schematic diagram of a switched transmission line 240according to another embodiment. The switched transmission line 240includes a transmission line 231, a first ground conductor 233 a, asecond ground conductor 233 b, and pairs of FET switches 232 a 1/232 a,232 b 1/232 b 2, 232 c 1/232 c 2, . . . 232 n 1/232 n 2. Thus, n pairsof shunt switches are included, where n is an integer of 2 or more, ormore preferably, 4 or more.

In comparison to the switched transmission line 230 of FIG. 4A, theswitched transmission line 240 of FIG. 5A implements each shunt switchusing a pair of FET switches. Additionally, each pair of FET switchesincludes one FET switch (for instance, FET switch 232 a 1) connectedbetween the transmission line 231 and the first ground conductor 233 aand another FET switch (for instance, FET switch 232 a 2) connectedbetween the transmission line 231 and the second ground conductor 233 b.In certain implementations, each pair of FET switches is commonlycontrolled by a corresponding control signal (for example, n controlsignals one for each pair generated by a control circuit, such as thecontrol circuit 223 of FIG. 4A).

By implementing the shunt switches using FETs in the manner depicted,enhanced performance (particularly at high frequencies) is achieved.

FIG. 5B is a schematic diagram of a switched transmission line 250according to another embodiment. The switched transmission line 250includes a transmission line 231, a first ground conductor 233 a, asecond ground conductor 233 b, and pairs of FET switches 242 a 1/242 a,242 b 1/242 b 2, 242 c 1/242 c 2, . . . 242 n 1/242 n 2.

The switched transmission line 250 of FIG. 5B is similar to the switchedtransmission line 240 of FIG. 5A, except that the switched transmissionline 250 of FIG. 5B includes shunt switches having different sizes (andthus varying on-state resistances and off-state capacitances) anddifferent distances or separations from one another.

Implementing the switched transmission line 250 in this manner providesa number of advantages.

For example, the on-state resistances (Ron) of the shunt switches can beindividually selected to keep substantially constant reflectioncoefficient (IΓ_(L)|) over switch states (which correspond to phaseshifting settings). In certain implementations, Ron can be decreased asphase shift increases, and thus switches closer to the transmissionline's RF input can be smaller (for higher on-state resistance) thanswitches further from the RF input.

In another example, the lengths of transmission line 231 (d₁, d₂, . . .d_(n)) between switches are selected to control an amount of phase stepbetween adjacent phase settings.

For instance, 11.25 degrees of phase step at a center frequency of 27GHz can be achieved by proper selection of the distances betweenswitches.

When implementing the switched transmission line 250, off-statecapacitance (Coff) is considered in terms of impact on thecharacteristic impedance and propagation constant of the transmissionline 231. For example, the switches and the transmission line can bedesigned simultaneously and iteratively.

FIG. 6 is a schematic diagram of a switched transmission line 260according to another embodiment. The switched transmission line 260includes a transmission line 251, an RF input RF_(IN) to thetransmission line 251, shunt switches 222 a, 222 b, 222 c, . . . 222 n,and a control circuit 223.

The switched transmission line 260 of FIG. 6 is similar to the switchedtransmission line 230 of FIG. 4A, except that the transmission line 251shown in FIG. 6 includes sections 255 a, 255 b, . . . 255 n that aremeandered to achieve desired phase and/or magnitude response whilemaintaining a compact layout.

Meandering of a transmission line is also applicable to configurationsusing pairs of FET switches coupled to a pair of grounding lines. Forexample, the transmission line 231 of the embodiments of FIGS. 5A and 5Bcan be meandered in accordance with the teachings herein.

FIG. 7 is a schematic diagram of a switched transmission line 310according to another embodiment. The switched transmission line 310includes a transmission line 301, a first ground conductor 302 a, asecond ground conductor 302 b, a first pair of switches 304 a-304 b, anda second pair of switches 305 a-305 b. Additional pairs of switches canbe included as indicated by the ellipsis.

In the example of FIG. 7, the transmission line 301 includes a firstsection 305 a meandered in a small loop and a second section 305 b thatis meandered without looping. The embodiment of FIG. 7 depicts anotherexample of meandering to achieve desired phase and/or magnitude responsewhile maintaining a compact layout.

A wide variety of performance results can be achieved using thereflective type phase shifters implemented in accordance with theteachings herein.

Table 1 below shows one example results for a phase shifter usingswitched transmission line loads in accordance with one implementationof FIG. 5B.

TABLE 1 Worse Case Insertion Loss Worse Case Insertion DifferenceAverage Return Loss Total Phase Phase RMS Loss RMS Between Two Insertionon Both Range (deg.) Error (deg.) Error (dB) States (dB) loss (dB) Ports(dB) 24 GHz 170 0.9 0.14 0.5 4.8 18 27 GHz 191 1.1 0.2 0.65 4.9 24 30GHz 215 1.6 0.28 0.9 5.1 18

FIG. 8 is a schematic diagram of one embodiment of a mobile device 800.The mobile device 800 includes a baseband system 801, a transceiver 802,a front end system 803, antennas 804, a power management system 805, amemory 806, a user interface 807, and a battery 808.

The mobile device 800 can be used communicate using a wide variety ofcommunications technologies, including, but not limited to, 2G, 3G, 4G(including LTE, LTE-Advanced, and LTE-Advanced Pro), 5G NR, WLAN (forinstance, Wi-Fi), WPAN (for instance, Bluetooth and ZigBee), WMAN (forinstance, WiMax), and/or GPS technologies.

The transceiver 802 generates RF signals for transmission and processesincoming RF signals received from the antennas 804. It will beunderstood that various functionalities associated with the transmissionand receiving of RF signals can be achieved by one or more componentsthat are collectively represented in FIG. 8 as the transceiver 802. Inone example, separate components (for instance, separate circuits ordies) can be provided for handling certain types of RF signals.

The front end system 803 aids is conditioning signals transmitted toand/or received from the antennas 804. In the illustrated embodiment,the front end system 803 includes phase shifters 810, power amplifiers(PAs) 811, low noise amplifiers (LNAs) 812, filters 813, switches 814,and duplexers 815.

The phase shifters 810 can be implemented in accordance with any of theembodiments herein. However, the phase shifters disclosed herein can beused in other configurations of electronic systems.

The front end system 803 can provide a number of functionalities,including, but not limited to, amplifying signals for transmission,amplifying received signals, filtering signals, switching betweendifferent bands, switching between different power modes, switchingbetween transmission and receiving modes, duplexing of signals,multiplexing of signals (for instance, diplexing or triplexing), or somecombination thereof.

The mobile device 800 operates with beamforming. For example, the frontend system 803 includes phase shifters 810 having variable phasecontrolled by the transceiver 802. In certain implementations, thetransceiver 802 controls the phase of the phase shifters 810 based ondata received from the processor 801.

The phase shifters 810 are controlled to provide beam formation anddirectivity for transmission and/or reception of signals using theantennas 804. For example, in the context of signal transmission, thephases of the transmit signals provided to an antenna array used fortransmission are controlled such that radiated signals combine usingconstructive and destructive interference to generate an aggregatetransmit signal exhibiting beam-like qualities with more signal strengthpropagating in a given direction. In the context of signal reception,the phases are controlled such that more signal energy is received whenthe signal is arriving to the antenna array from a particular direction.

In certain implementations, the mobile device 800 supports carrieraggregation, thereby providing flexibility to increase peak data rates.Carrier aggregation can be used for both Frequency Division Duplexing(FDD) and Time Division Duplexing (TDD), and may be used to aggregate aplurality of carriers or channels. Carrier aggregation includescontiguous aggregation, in which contiguous carriers within the sameoperating frequency band are aggregated. Carrier aggregation can also benon-contiguous, and can include carriers separated in frequency within acommon band or in different bands.

The antennas 804 can include antennas used for a wide variety of typesof communications. For example, the antennas 804 can include antennasfor transmitting and/or receiving signals associated with a wide varietyof frequencies and communications standards.

In certain implementations, the antennas 804 support MIMO communicationsand/or switched diversity communications. For example, MIMOcommunications use multiple antennas for communicating multiple datastreams over a single radio frequency channel. MIMO communicationsbenefit from higher signal to noise ratio, improved coding, and/orreduced signal interference due to spatial multiplexing differences ofthe radio environment. Switched diversity refers to communications inwhich a particular antenna is selected for operation at a particulartime. For example, a switch can be used to select a particular antennafrom a group of antennas based on a variety of factors, such as anobserved bit error rate and/or a signal strength indicator.

In certain implementations, the antennas 804 include one or more arraysof antenna elements to enhance beamforming.

The baseband system 801 is coupled to the user interface 807 tofacilitate processing of various user input and output (I/O), such asvoice and data. The baseband system 801 provides the transceiver 802with digital representations of transmit signals, which the transceiver802 processes to generate RF signals for transmission. The basebandsystem 801 also processes digital representations of received signalsprovided by the transceiver 802. As shown in FIG. 8, the baseband system801 is coupled to the memory 806 of facilitate operation of the mobiledevice 800.

The memory 806 can be used for a wide variety of purposes, such asstoring data and/or instructions to facilitate the operation of themobile device 800 and/or to provide storage of user information.

The power management system 805 provides a number of power managementfunctions of the mobile device 800. In certain implementations, thepower management system 805 includes a PA supply control circuit thatcontrols the supply voltages of the power amplifiers 811. For example,the power management system 805 can be configured to change the supplyvoltage(s) provided to one or more of the power amplifiers 811 toimprove efficiency, such as power added efficiency (PAE).

As shown in FIG. 8, the power management system 805 receives a batteryvoltage from the battery 808. The battery 808 can be any suitablebattery for use in the mobile device 800, including, for example, alithium-ion battery.

FIG. 9A is a schematic diagram of an RF channel 910 according to oneembodiment. The RF channel 910 includes an RF splitter/combiner 901,phase shifters 902 a, 902 b, . . . 902 z, a first group oftransmit/receive (T/R) switches 903 a, 903 b, . . . 903 z, poweramplifiers 904 a, 904 b, . . . 904 z, low noise amplifiers (LNAs) 905 a,905 b, . . . 905 z, a second group of T/R switches 906 a, 906 b, . . .906 z, and antennas 907 a, 907 b, . . . 907 z.

In the illustrated embodiment, T/R switches are used to selecting thepower amplifiers for transmit or the LNAs for receive. Thus, the RFchannel 910 is suitable for time division duplexing (TDD). Additionally,the RF splitter/combiner 901 is shared for the transmit and receivedirections, thus reducing RF signal routes.

Although one embodiment of an RF channel is depicted, the teachingsherein are applicable to RF channels implemented in a wide variety ofways. Accordingly, other implementations are possible.

FIG. 9B is a schematic diagram of an RF channel 920 according to anotherembodiment. The RF channel 920 includes an RF splitter 911 a, an RFcombiner 911 b, a first group of phase shifters 912 a, 912 b, . . . 912z, a second group of phase shifters 913 a, 913 b, . . . 913 z, poweramplifiers 904 a, 904 b, . . . 904 z, LNAs 905 a, 905 b, . . . 905 z,T/R switches 906 a, 906 b, . . . 906 z, and antennas 907 a, 907 b, . . .907 z.

The RF channel 920 illustrated another embodiment of an RF channel.However, the teachings herein are applicable to RF channels implementedin a wide variety of ways. Accordingly, other implementations arepossible.

FIG. 10A is a perspective view of one embodiment of a module 1140 thatoperates with beamforming. FIG. 10B is a cross-section of the module1140 of FIG. 10A taken along the lines 10B-10B.

The module 1140 includes a laminated substrate or laminate 1141, asemiconductor die or IC 1142 (not visible in FIG. 10A), surface mountdevices (SMDs) 1143 (not visible in FIG. 10A), and an antenna arrayincluding antenna elements 1151 a 1, 1151 a 2, 1151 a 3 . . . 1151 an,1151 b 1, 1151 b 2, 1151 b 3 . . . 1151 bn, 1151 c 1, 1151 c 2, 1151 c 3. . . 1151 cn, 1151 m 1, 1151 m 2, 1151 m 3 . . . 1151 mn.

Although one embodiment of a module is shown in FIGS. 10A and 10B, theteachings herein are applicable to modules implemented in a wide varietyof ways. For example, a module can include a different arrangement ofand/or number of antenna elements, dies, and/or surface mount devices.Additionally, the module 1140 can include additional structures andcomponents including, but not limited to, encapsulation structures,shielding structures, and/or wirebonds.

The antenna elements antenna elements 1151 a 1, 1151 a 2, 1151 a 3 . . .1151 an, 1151 b 1, 1151 b 2, 1151 b 3 . . . 1151 bn, 1151 c 1, 1151 c 2,1151 c 3 . . . 1151 cn, 1151 m 1, 1151 m 2, 1151 m 3 . . . 1151 mn areformed on a first surface of the laminate 1141, and can be used toreceive and/or transmit signals, based on implementation. Although a 4×4array of antenna elements is shown, more or fewer antenna elements arepossible as indicated by ellipses. Moreover, antenna elements can bearrayed in other patterns or configurations, including, for instance,arrays using non-uniform arrangements of antenna elements. Furthermore,in another embodiment, multiple antenna arrays are provided, such asseparate antenna arrays for transmit and receive and/or for differentcommunication bands.

In the illustrated embodiment, the IC 1142 is on a second surface of thelaminate 1141 opposite the first surface. However, other implementationsare possible. In one example, the IC 1142 is integrated internally tothe laminate 1141.

In certain implementations, the IC 142 includes signal conditioningcircuits associated with the antenna elements 1151 a 1, 1151 a 2, 1151 a3 . . . 1151 an, 1151 b 1, 1151 b 2, 1151 b 3 . . . 1151 bn, 1151 c 1,1151 c 2, 1151 c 3 . . . 1151 cn, 1151 m 1, 1151 m 2, 1151 m 3 . . .1151 mn. Such signal conditioning circuits can include one or more phaseshifters 1145 implemented in accordance with the teachings herein.

In one embodiment, the IC 1142 includes a serial interface, such as amobile industry processor interface radio frequency front-end (MIPIRFFE) bus and/or inter-integrated circuit (I2C) bus that receives datafor controlling the signal conditioning circuits, such as the amount ofphase shifting provided by the phase shifters 1145. In anotherembodiment, the IC 142 further includes an integrated transceiver.

The laminate 1141 can include various structures including, for example,conductive layers, dielectric layers, and/or solder masks. The number oflayers, layer thicknesses, and materials used to form the layers can beselected based on a wide variety of factors, and can vary withapplication and/or implementation. The laminate 1141 can include viasfor providing electrical connections to signal feeds and/or ground feedsof the antenna elements. For example, in certain implementations, viascan aid in providing electrical connections between signal conditioningcircuits of the IC 1142 and corresponding antenna elements.

The antenna elements 1151 a 1, 1151 a 2, 1151 a 3 . . . 1151 an, 1151 b1, 1151 b 2, 1151 b 3 . . . 1151 bn, 1151 c 1, 1151 c 2, 1151 c 3 . . .1151 cn, 1151 m 1, 1151 m 2, 1151 m 3 . . . 1151 mn can correspond toantenna elements implemented in a wide variety of ways. In one example,the array of antenna elements includes patch antenna element formed froma patterned conductive layer on the first side of the laminate 1141,with a ground plane formed using a conductive layer on opposing side ofthe laminate 1141 or internal to the laminate 1141. Other examples ofantenna elements include, but are not limited to, dipole antennaelements, ceramic resonators, stamped metal antennas, and/or laserdirect structuring antennas.

The module 1140 can be included in a communication system, such as amobile phone or base station. In one example, the module 1140 isattached to a phone board of a mobile phone.

Applications

The principles and advantages of the embodiments described herein can beused for a wide variety of applications.

For example, phase shifters can be included in various electronicdevices, including, but not limited to consumer electronic products,parts of the consumer electronic products, electronic test equipment,etc. Example electronic devices include, but are not limited to, a basestation, a wireless network access point, a mobile phone (for instance,a smartphone), a tablet, a television, a computer monitor, a computer, ahand-held computer, a personal digital assistant (PDA), a microwave, arefrigerator, an automobile, a stereo system, a disc player, a digitalcamera, a portable memory chip, a washer, a dryer, a copier, a facsimilemachine, a scanner, a multi-functional peripheral device, a wrist watch,a clock, etc. Further, the electronic devices can include unfinishedproducts.

CONCLUSION

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The word “coupled”, as generally usedherein, refers to two or more elements that may be either directlyconnected, or connected by way of one or more intermediate elements.Likewise, the word “connected”, as generally used herein, refers to twoor more elements that may be either directly connected, or connected byway of one or more intermediate elements. Additionally, the words“herein,” “above,” “below,” and words of similar import, when used inthis application, shall refer to this application as a whole and not toany particular portions of this application. Where the context permits,words in the above Detailed Description using the singular or pluralnumber may also include the plural or singular number respectively. Theword “or” in reference to a list of two or more items, that word coversall of the following interpretations of the word: any of the items inthe list, all of the items in the list, and any combination of the itemsin the list.

Moreover, conditional language used herein, such as, among others,“can,” “could,” “might,” “may,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states. Thus, such conditional language is notgenerally intended to imply that features, elements and/or states are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or withoutauthor input or prompting, whether these features, elements and/orstates are included or are to be performed in any particular embodiment.

The above detailed description of embodiments of the invention is notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whileprocesses or blocks are presented in a given order, alternativeembodiments may perform routines having steps, or employ systems havingblocks, in a different order, and some processes or blocks may bedeleted, moved, added, subdivided, combined, and/or modified. Each ofthese processes or blocks may be implemented in a variety of differentways. Also, while processes or blocks are at times shown as beingperformed in series, these processes or blocks may instead be performedin parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the disclosure. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the disclosure.

What is claimed is:
 1. A phase shifter comprising: a first port and asecond port; a first controllable reflective load including a firsttransmission line and a first plurality of shunt switches connectedalong the first transmission line; a second controllable reflectiveload; and a pair of coupled lines that are electromagnetically coupledto one another, the pair of coupled lines including a first conductiveline connected between the first port and the first controllablereflective load and a second conductive line connected between thesecond controllable reflective load and the second port.
 2. The phaseshifter of claim 1 wherein the first controllable reflective loadfurther includes a first ground conductor on a first side of the firsttransmission line and a second ground conductor on a second side of thefirst transmission line.
 3. The phase shifter of claim 2 wherein each ofthe first plurality of shunt switches is implemented as a pair offield-effect transistors including a first field-effect transistorconnected between the first transmission line and the first groundconductor and a second field-effect transistor connected between thefirst transmission line and the second ground conductor.
 4. The phaseshifter of claim 1 wherein one or more of the first plurality of shuntswitches are closed based on a phase shifting setting of the phaseshifter.
 5. The phase shifter of claim 1 wherein the first port receivesa radio frequency input signal and the second port provides aphase-shifted radio frequency output signal.
 6. The phase shifter ofclaim 1 wherein the second port receives a radio frequency input signaland the first port provides a phase-shifted radio frequency outputsignal.
 7. The phase shifter of claim 1 wherein the first plurality ofshunt switches are connected to the first transmission line at aplurality of points having non-uniform distance from one another.
 8. Thephase shifter of claim 7 wherein the distance between adjacent pairs ofthe plurality of points gradually decreases along a length of the firsttransmission line.
 9. The phase shifter of claim 1 wherein the firstplurality of shunt switches each have a different size.
 10. The phaseshifter of claim 9 wherein the size of the first plurality of shunttransistors gradually increases along a length of the first transmissionline.
 11. The phase shifter of claim 1 wherein the first transmissionline includes a plurality of meandering sections.
 12. The phase shifterof claim 11 wherein at least one of the plurality of meandering sectionsincludes a loop.
 13. The phase shifter of claim 1 wherein the secondcontrollable reflective load includes a second transmission line and asecond plurality of shunt switches connected along the secondtransmission line.
 14. A wireless device comprising: a transceiver; anda front-end system coupled to the transceiver, the front-end systemincluding a phase shifter including a first port, a second port, a firstcontrollable reflective load including a first transmission line and afirst plurality of shunt switches connected along the first transmissionline, a second controllable reflective load, and a pair of coupled linesthat are electromagnetically coupled to one another, the pair of coupledlines including a first conductive line connected between the first portand the first controllable reflective load and a second conductive lineconnected between the second controllable reflective load and the secondport.
 15. The wireless device of claim 14 wherein the first controllablereflective load further includes a first ground conductor on a firstside of the first transmission line and a second ground conductor on asecond side of the first transmission line.
 16. The wireless device ofclaim 15 wherein each of the first plurality of shunt switches isimplemented as a pair of field-effect transistors including a firstfield-effect transistor connected between the first transmission lineand the first ground conductor and a second field-effect transistorconnected between the first transmission line and the second groundconductor.
 17. The wireless device of claim 14 wherein one or more ofthe first plurality of shunt switches are closed based on a phaseshifting setting of the phase shifter.
 18. The wireless device of claim14 wherein the first plurality of shunt switches are connected to thefirst transmission line at a plurality of points having non-uniformdistance from one another.
 19. The wireless device of claim 14 whereinthe first plurality of shunt switches each have a different size.
 20. Amethod of phase shifting, the method comprising: receiving a radiofrequency input signal at a first port; controlling a first controllablereflective load and a second controllable reflective load to control aphase shift of a radio frequency output signal at a second port, thefirst controllable reflective load including a first transmission lineand a first plurality of shunt switches connected along the firsttransmission line; and providing coupling between a first conductiveline and a second conductive line of a pair of coupled lines, the firstconductive line connected between the first port and the firstcontrollable reflective load, and the second conductive line connectedbetween the second controllable reflective load and the second port.